Controlled reproducible alignment of cone targets and mitigation of preplasma in high intensity laser interactions

Abstract

The use of cone targets in high intensity laser-plasma experiments has been of recent interest because of their potential use in integrated fast ignition experiments. Simpler experiments provide a good avenue for understanding the underlying physics, however precise control of the alignment along with good pointing accuracy is of crucial importance. While on big laser facilities target alignment is done precisely with several microscopes, it is not always the case on smaller facilities. This can have a detrimental effect on the quality of the results. We have developed and characterized a method for accurate alignment of intense laser pulses into a cone target. This, along with optimal positioning of the focus compared to the tip, efficiently uses the shape of the target to microfocus the laser light and concentrates the hot electrons in the tip, and can mitigate preplasma issues.